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KNOW A SCIENTIST
Dr. Susumu Tonegawa, most notably, she received the Nobel Prize for Physiology or Medicine in 1983, the first woman to win that prize credited by the Nobel Foundation for discovering "mobile genetic elements"; it was more than 30 years after she initially described the phenomenon of controlling elements. She was compared to Gregor Mendel in terms of her scientific career by the Swedish Academy of Sciences when she was awarded the Prize.
Protein disrupts infectious biofilms
Many infectious pathogens are difficult to treat because they develop into biofilms, layers of metabolically active but slowly growing bacteria embedded in a protective layer of slime, which are inherently more resistant to antibiotics. Now, a group of researchers at Caltech and the University of Oxford have made progress in the fight against biofilms. Led by Dianne Newman, the Gordon M. Binder/Amgen Professor of Biology and Geobiology, the group identified a protein that degrades and inhibits biofilms of Pseudomonas aeruginosa, the primary pathogen in cystic fibrosis (CF) infections.
Pseudomonas aeruginosa causes chronic infections that are difficult to treat, such as those that inhabit burn wounds, diabetic ulcers, and the lungs of individuals living with cystic fibrosis. Newman says. "In part, the reason these infections are hard to treat is because P. aeruginosa enters a biofilm mode of growth in these contexts; biofilms tolerate conventional antibiotics much better than other modes of bacterial growth. Our research suggests a new approach to inhibiting P. aeruginosa biofilms.”
The group targeted pyocyanin, a small molecule produced by P. aeruginosa that produces a blue pigment. Pyocyanin has been used in the clinical identification of this strain for over a century, but several years ago the Newman group demonstrated that the molecule also supports biofilm growth, raising the possibility that its degradation might offer a new route to inhibit biofilm development.
To identify a factor that would selectively degrade pyocyanin, Kyle Costa, a postdoctoral scholar in biology and biological engineering, turned to a milligram of soil collected in the courtyard of the Beckman Institute on the Caltech campus. From the soil, he isolated another bacterium, Mycobacterium fortuitum, which produces a previously uncharacterized small protein called pyocyanin demethylase (PodA).
Crystal structure of the PodA protein complex with three molecules of 1-hydroxyphenazine, the reaction product, bound in the active sites.
Image Credit: Kyle Costa/Caltech
Source: www.sciencedaily.com
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